Imaging apparatus for controlling fluorescence imaging in divided imaging surface

Abstract

An imaging apparatus includes: an excitation light emission unit that irradiates a subject with excitation light for exciting a fluorescent substance introduced into the subject; a normal light emission unit that irradiates the subject with normal light including a visible wavelength range different from the excitation light; an imaging unit that forms an optical image of the subject irradiated with the excitation light or normal light on an imaging surface to generate an image signal; a brightness signal generation unit that generates a brightness signal indicating brightness, based on the image signal generated by the imaging unit under irradiation with the normal light; and an amplification unit that sets an amplification factor of the image signal to be generated by the imaging unit under irradiation with the excitation light, based on an amplification factor of the image signal according to the brightness signal generated by the brightness signal generation unit.

What is claimed is: 
     
       1. An imaging apparatus comprising:
 an excitation light emission unit configured to irradiate a subject with excitation light for exciting a fluorescent substance introduced into the subject; 
 a normal light emission unit configured to irradiate the subject with normal light including a visible wavelength range different from the excitation light; 
 an imaging unit configured to form an optical image of the subject irradiated with the excitation light or normal light on an imaging surface to generate an image signal; 
 a brightness signal generation unit configured to generate a brightness signal indicating brightness, based on the image signal generated by the imaging unit under irradiation with the normal light; 
 an amplification unit configured to set an amplification factor of the image signal to be generated by the imaging unit under irradiation with the excitation light, based on an amplification factor of the image signal according to the brightness signal generated by the brightness signal generation unit; 
 a divided region setting unit configured to divide the imaging surface to set a plurality of divided regions; and 
 a fluorescence determination unit configured to determine presence or absence of a fluorescence region that emits fluorescence in a fluorescence image corresponding to the image signal generated under irradiation with the excitation light, 
 wherein the brightness signal generation unit is configured to generate brightness signals of the plurality of divided regions set by the divided region setting unit, 
 wherein based on an amplification factor according to each of the brightness signals, the amplification unit is configured to set an amplification factor of the image signal corresponding to each of the divided regions under irradiation with the excitation light, 
 wherein when the fluorescence determination unit determines that there is the fluorescence region in the fluorescence image, the divided region setting unit divides the divided region including the fluorescence region to set a plurality of small divided regions, and 
 wherein based on the amplification factor according to each of the brightness signals, the amplification unit is configured to set an amplification factor of the image signal corresponding to each of the small divided regions under irradiation with the excitation light. 
 
     
     
       2. The imaging apparatus according to  claim 1 ,
 wherein the amplification unit is configured to set the amplification factor of the image signal based on a gain. 
 
     
     
       3. The imaging apparatus according to  claim 1 ,
 wherein the amplification unit is configured to set the amplification factor of the image signal based on an exposure time. 
 
     
     
       4. The imaging apparatus according to  claim 1 ,
 wherein the divided region setting unit is configured to divide each of the divided regions to set a plurality of small divided regions, and 
 wherein based on the amplification factor according to each of the brightness signals, the amplification unit is configured to set an amplification factor of the image signal corresponding to each of the small divided regions under irradiation with the excitation light. 
 
     
     
       5. An imaging apparatus comprising:
 an excitation light emission unit configured to irradiate a subject with excitation light for exciting a fluorescent substance introduced into the subject; 
 a normal light emission unit configured to irradiate the subject with normal light including a visible wavelength range different from the excitation light; 
 an imaging unit configured to form an optical image of the subject irradiated with the excitation light or normal light on an imaging surface to generate an image signal; 
 a brightness signal generation unit configured to generate a brightness signal indicating brightness, based on the image signal generated by the imaging unit under irradiation with the normal light; 
 an amplification unit configured to set an amplification factor of the image signal to be generated by the imaging unit under irradiation with the excitation light, based on an amplification factor of the image signal according to the brightness signal generated by the brightness signal generation unit; 
 a divided region setting unit configured to divide the imaging surface to set a plurality of divided regions; and 
 a fluorescence determination unit configured to determine presence or absence of a fluorescence region that emits fluorescence in a fluorescence image corresponding to the image signal generated under irradiation with the excitation light, 
 wherein the brightness signal generation unit is configured to generate brightness signals of the plurality of divided regions set by the divided region setting unit, 
 wherein based on an amplification factor according to each of the brightness signals, the amplification unit is configured to set an amplification factor of the image signal corresponding to each of the divided regions under irradiation with the excitation light, and 
 wherein when the fluorescence determination unit determines that there is the fluorescence region in the fluorescence image, the divided region setting unit makes the divided region including the fluorescence region smaller with lapse of time. 
 
     
     
       6. The imaging apparatus according to  claim 5 ,
 wherein the amplification unit is configured to set the amplification factor of the image signal based on a gain. 
 
     
     
       7. The imaging apparatus according to  claim 5 ,
 wherein the amplification unit is configured to set the amplification factor of the image signal based on an exposure time. 
 
     
     
       8. The imaging apparatus according to  claim 5 ,
 wherein the divided region setting unit is configured to divide each of the divided regions to set a plurality of small divided regions, and 
 wherein based on the amplification factor according to each of the brightness signals, the amplification unit is configured to set an amplification factor of the image signal corresponding to each of the small divided regions under irradiation with the excitation light.